Hi,
Not sure if this is what you want but recently I have implemented a dynamic
delegate usage by using the Component class.
DeviceParameterView had three types: button, option, slider. I want to render a
different delegate depending on the type of the parameter model. This was the
solution I have implemented since instantiating the three different delegates
inside the delegate was killing list performance.
This approach will asynchronously load the specified component.
import QtQuick 2.2
Item {
id: root
clip: true
property var parameter
property Component component
property DeviceParameterButton button
property DeviceParameterOption option
property DeviceParameterSlider slider
Component.onDestruction: {
if (button!=null)
button.destroy()
if (option!=null)
option.destroy()
if (slider!=null)
slider.destroy()
}
onParameterChanged: {
switch (parameter.type)
{
case 0:
component = Qt.createComponent("DeviceParameterButton.qml");
var incubator = component.incubateObject(root, {"height": 20,
"parameter": parameter});
if (incubator.status != Component.Ready)
{
incubator.onStatusChanged = function(status)
{
if (status == Component.Ready)
{
button = incubator.object
root.width = button.width
}
}
}
break;
...
}
}
}
> On 17 Nov 2014, at 03:18, mark diener <rpzrpz...@gmail.com> wrote:
>
> Even:
>
> A couple months back you gave an intelligent answer from a interest list
> query about
> creating complex list views.
>
> I was a little tied up with things and could not get around to actually
> create a working example of a complex list view. Now is that time.
>
> Maybe you could get me past some implementation uncertainties
>
> Attached below is a copy of the original message.
>
> I am having trouble defining a loader that does not need a separate QML file
> for its definition, but a javascript function that is away of which row index
> of the model it is currently drawing and can pass that to a javacript
> function that will return a Component value directly instead of a reference
> to an QML file.
>
> I have included a small snippet QML file below:
>
> ListModel {
> id: glistdata
> {
> type: 1
> name : "Joe Perra"
> cell: "555-1212"
> eyes: "blue"
> mood: "sad"
> }
> ListElement
> {
> type: 2
> name : "Mary Tyler"
> cell: "555-1213"
> eyes: "brown"
> mood: "happy"
> }
> ListElement
> {
> type: 3
> name : "Peter Gabriel"
> cell: "555-1214"
> eyes: "blue"
> mood: "bitter"
> }
> }
>
> Component {
> id: gflavorone
> Item
> {
> Text
> {
> text: 'Name:' + name
> }
> Text
> {
> text: 'Mood:' + mood
> }
> }
>
> Component {
> id: gflavortwo
> Item
> {
> Text
> {
> text: 'Name:' + name
> }
> Text
> {
> text: 'Eyes:' + eyes
> }
> }
>
> Component {
> id: gflavorthree
> Item
> {
> Text
> {
> text: 'Name:' + name
> }
> Text
> {
> text: 'cell:' + cell
> }
> }
>
> Loader {
> id: gloader
>
> function getComp(gidx)
> {
> switch (gidx)
> {
> case 1: return gflavorone
> case 2: return gflavortwo
> }
> //Default case
> return gflavorthree
> }
> }
> sourceComponent: getComp(index)
> }
>
> ListView {
> id: glistview
> anchors.margins: 0
> anchors.fill: parent
> delegate: gloader
> model: glistdata
>
> }
>
>
> Maybe you or anybody else has some ideas on how to specifically code the
> Loader written to
> a dynamic Component instead of referring to an external QML file to generate
> the Component value.
>
> And on top of that, how does the loader getComp( ) function access the index
> of the row or maybe it must just only refer to the model fields
>
> So yes, I would like the Loader to intelligently select the sourceComponent
> using a dynamic function attached to the loader.
>
> This is an area that needs maybe a long experience QT veteran to comment on
> this.
>
>
> Cheers,
>
> md
>
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> > Subject: [Interest] Qt Quick 2.x Complex ListView
> >
> > Hello QTers:
>
> > Does anybody have an idea on how to create each row of the listview with a
> > delegate that allows for each row > to be rendered with separate logic
> > instead of the standard delegate which renders each row with the same or >
> > very similar logic.
>
> > Any comments or tips would be useful and I am sure more people would like
> > this option
>
> Not sure if it covers what you need, but I believe the common way to
> solve this is through using a Loader element as the delegate and
> changing the source depending on your criteria for which row delegate to
> use on the fly.
>
> ListView {
> id: example
> delegate: Loader {
> function getDelegate() { ... }
> source: getDelegate()
> }
> }
>
> Use the getDelegate() function to return the url for the delegate to use.
>
> You can use a similar trick inside the delegate item itself instead (or
> in addition) if you create separate elements for the different type of
> columns that you need to render, then you can use a Row with Loaders for
> example.
>
>
> -Ev
> _______________________________________________
> Interest mailing list
> Interest@qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
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